Evaluation of Traits Associated with Bucking Bull
Total Page:16
File Type:pdf, Size:1020Kb
EVALUATION OF TRAITS ASSOCIATED WITH BUCKING BULL PERFORMANCE AND BEHAVIOR A Thesis by NATASHA ELIZABETH ROMERO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2008 Major Subject: Animal Science EVALUATION OF TRAITS ASSOCIATED WITH BUCKING BULL PERFORMANCE AND BEHAVIOR A Thesis by NATASHA ELIZABETH ROMERO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Co-Chairs of Committee, Andy D. Herring Theodore Friend Committee Member, R. Neil Hooper Head of Department, Gary R. Acuff December 2008 Major Subject: Animal Science iii ABSTRACT Evaluation of Traits Associated with Bucking Bull Performance and Behavior. (December 2008) Natasha Elizabeth Romero, B.S., Texas A&M University Co-Chairs of Advisory Committee: Dr. Andy D. Herring Dr. Theodore Friend Video and industry data were used to assess the inter-relationships of aggression, delivery, coat color, year of birth, number of outs, buckoff percent and score in rodeo bulls. An evaluation of laterality based on observations of how the individual animals were loaded into chutes at 11 bull riding events showed 63% left-handed delivery and 37% right-handed delivery across all observations (n = 525). There was a similar distribution for aggressiveness (based on whether or not the bull charged after the rider dismounted) with 64% of bulls being non-aggressive and 36% of bulls being aggressive. Significant linear relationships existed between score and number of outs and score and buckoff percentage indicating that experience impacted performance. The correlation between number of outs and buckoff percentage was low to moderate (0.06 to 0.30), depending upon the subset of data evaluated. The r-square value for the analysis of score among all bulls was 0.14; however, the r-square value in the subset of bulls with known sires with more than one son was 0.68 when sire was included in the model. Similar increases in r-square values were observed for 2006 average score, career average score, buckoff percentage, and career iv buckoff percentage, indicating important genetic influences on these traits and/or their component traits. Investigations into the relationship between performance and aggression may help bucking stock producers improve the selection criteria they use. The current trend within the industry is for several breeders to breed ‘hot’ or flighty, nervous cattle to achieve higher performing offspring. Given that there was no association between aggression and score based on chi-square test, aggression may be removed from the criteria for using certain animals for breeding purposes. Based on results from this work, if bucking stock breeders want to make genetic changes in these traits, documentation of pedigree information is vital. v ACKNOWLEDGMENTS I would like to thank the American Bucking Bull Inc. for their support in providing me access to pedigree information from their registry. I would like to thank the Professional Bull Riders for allowing me access to rodeo events for data collection. Special thanks go to Bull Pen magazine that has stood behind me and made their resources available during this project. I would also like to thank the following ranches for their time and effort in this project: Guidry Land and Cattle Co., B-K Rodeo, Lufkin Ranch and Rodeo, Frontier Rodeo, Wilfong Rodeo, XS Ranch and Double R Rodeo. I would like to thank the co-chairs of my committee, Dr. Andy Herring and Dr. Ted Friend for their support, guidance and most importantly, for their patience and understanding during my graduate career. I would also like to thank Dr. Hooper for his participation as my committee member. I would like to acknowledge my mom, Frances Bassett, and my aunt and uncle, Robert and Kim Romero, for all of their love and support during my academic career. vi NOMENCLATURE DAB Dataset “All Bulls” DBG Dataset “Bull Groups” DS Dataset “Sires” DS1 Dataset “Sires with more than 1 son” vii TABLE OF CONTENTS Page ABSTRACT.............................................................................................................. iii ACKNOWLEDGEMENTS ...................................................................................... iv NOMENCLATURE.................................................................................................. vi TABLE OF CONTENTS.......................................................................................... vii LIST OF TABLES .................................................................................................... ix INTRODUCTION..................................................................................................... 1 LITERATURE REVIEW.......................................................................................... 4 Temperament and behavior........................................................................... 4 Evolution of bucking behavior...................................................................... 5 Maternal behavior ......................................................................................... 6 Coat color and temperament ......................................................................... 8 Physiology of stress....................................................................................... 10 Laterality ....................................................................................................... 11 Influence of the flank strap............................................................................ 14 OBJECTIVES ........................................................................................................... 16 MATERIALS AND METHODS .............................................................................. 17 Animals ......................................................................................................... 17 Video collection ............................................................................................ 17 Rodeo events attended................................................................................... 18 Aggression..................................................................................................... 18 Coat color ...................................................................................................... 19 Buckoff.......................................................................................................... 19 Career buckoff............................................................................................... 19 Outs ............................................................................................................... 19 Career outs..................................................................................................... 20 Laterality ....................................................................................................... 20 Animal pedigree ............................................................................................ 20 Animal year of birth ...................................................................................... 20 viii Page Score.............................................................................................................. 21 Average score................................................................................................ 22 Career average score ..................................................................................... 22 Datasets ......................................................................................................... 22 Statistical analysis ......................................................................................... 22 RESULTS AND DISCUSSION ............................................................................... 25 GENERAL CONCLUSIONS AND IMPLICATIONS ............................................ 58 Aggression..................................................................................................... 58 Laterality ....................................................................................................... 59 Pedigree information..................................................................................... 59 LITERATURE CITED ............................................................................................. 62 VITA ........................................................................................................................ 66 ix LIST OF TABLES Page Table 1 Levels of significance (P- values) from analyses of variance for DAB............................................................................................. 27 Table 2 Regression coefficients (and standard errors) across datasets to evaluate average score and career average score .......................... 28 Table 3 Levels of significance (P- values) from analyses of variance for DSI............................................................................................... 30 Table 4 Levels of significance (P- values) from analyses of variance for DBG............................................................................................. 31 Table 5 Levels of significance (P-values) from analyses of variance for DS ................................................................................................ 33 Table 6 Least squares means and standard errors for color across